Set default font to sans-serif

Change-Id: Ia97cde486c7a92081bdcfbad8c84311c409d2c43
diff --git a/dev/scss/base.scss b/dev/scss/base.scss
index 68854fb..99fe4c8 100644
--- a/dev/scss/base.scss
+++ b/dev/scss/base.scss
@@ -12,7 +12,7 @@
 select,
 g > text {
   color: $dark-grey;
-  font-family: verdana, tahoma, arial;
+  font-family: verdana, tahoma, arial, Helvetica, sans-serif;
   margin: 0;
 }